Coronary arteries.

Coronary angiography (CA) is presently considered the gold standard for the assessment of the coronary arteries. However, the presence of ionizing radiation, its invasiveness and the small associated risk of morbidity prompted long ago the development of more patient-friendly imaging modalities. A promising technique, magnetic resonance imaging (MRI), has been regarded as the major modality in the coming decade. Although still in its infancy qualitatively, its flexibility and non-invasiveness opens the door for a comprehensive evaluation of the heart and the coronary arteries in one single sitting with high anatomical definition and excellent soft tissue contrast capabilities, double-oblique tomographic sections and the possibility to quantify an innumerable number of cardiovascular physiological parameters. Numerous ideas have been assessed, comprising breath-hold and free-breathing two-dimensional and three-dimensional measurements. New ongoing trials with intravascular contrast agents may provide for all these techniques the long-awaited essential boost for reliable magnetic resonance coronary angiography (MRCA). Introduction of parallel MRI acquisition techniques, such as simultaneous acquisition of spatial harmonics (SMASH) and sensitivity encoding (SENSE) may provide the speed enhancement required to shorten imaging time for all techniques explored to date.